The investigators have invented a very simple, but extremely powerful, new technology for detection and identification of volatile organic compounds (VOCs): colorimetric sensor arrays. These are inexpensive, disposable sensor arrays based on equilibrium interactions of analytes with metalloporphyrins and other chemically responsive dyes. As with human olfaction, our colorimetric sensor arrays use a large number of cross-reactive sensors that probe a wide range of chemical properties. By digitally monitoring the change in color of each dye in the array, they have a quantitative measure of a composite response to volatile organics. Chemometric pattern recognition is extremely powerful with these arrays because of their very high dimensionality. the investigators are now extending this work to biomedical applications, with specific aims focusing on the development of a personal chemical dosimeter for the detection, identification, and quantification of environmental/workplace VOCs. The sensitivity of the arrays permits rapid detection of very low levels of most volatile toxicants. This is a translational technology that should find substantial use in workplace monitoring of chemical exposure. Their efforts in these areas should lead (1) to fundamental advances in sensor development for molecular recognition and biomedical applications of such sensor arrays, (2) development and refinement of technology for the rapid and continuous identification and quantitation of volatile chemical toxicants, and most importantly, (3) prototyping of an extremely portable device for the assessment of personal VOC exposure;this device will provide continuous, quantitative, reliable, reproducible, multiplexed measurement of environmental exposures with rapid response (i.e., seconds) that requires essentially no user intervention for field deployment and data capture. This self-contained, easy-to-use device will prove ideal for multi-analyte measurement of point-of-contact exposures to priority environmental chemicals for use within future population-based biomedical studies of diverse populations. The device will be able to measure analyte concentrations continuously, will require essentially no user intervention for field deployment and data capture, and will be capable of real-time telemetry to a centralized system.